The motion of a mass on an inclined plane is perhaps the most classic introductory mechanics problem. Over the years, as a student, and then later as a physics teacher, I have analyzed more than my fair share of these kinds of scenarios. I must admit, as an engineer, I have yet to encounter a problem of this type in the field – I have never been asked to design a block or inclined plane, nor have I been asked to verify whether Newton’s 3+ Century-old laws still apply to it.
Do I think all of the time that physics students spend examining masses on inclined planes is wasted? Of course not – the simple scenario clearly illustrates the most important law of mechanics (Newton’s Second Law), and is a necessary stepping stone towards analyzing more complex situations.
There is, I believe, a secondary usefulness to examining such systems that extends beyond the practical realm. Let us take a close look at a mass as it slides up or down a banked surface; I contend that it serves as a powerful metaphor for life.
I know what you are thinking: this guy has drawn one too many free body diagrams. Correct.